BACKGROUND: Non-invasive vagus nerve stimulation (nVNS) has been shown to be practical, safe, and well tolerated for treating primary headache disorders. The recent multicenter, randomized, double-blind, sham-controlled PRESTO trial provided Class I evidence that for patients with episodic migraine, nVNS significantly increases the probability of having mild pain or being pain-free 2 h post stimulation. We report additional pre-defined secondary and other end points from PRESTO that demonstrate the consistency and durability of nVNS efficacy across a broad range of outcomes.METHODS: After a 4-week observation period, 248 patients with episodic migraine with/without aura were randomly assigned to acute treatment of migraine attacks with nVNS (n = 122) or a sham device (n = 126) during a double-blind period lasting 4 weeks (or until the patient had treated 5 attacks). All patients received nVNS therapy during the subsequent 4-week/5-attack open-label period.RESULTS: The intent-to-treat population consisted of 243 patients. The nVNS group (n = 120) had a significantly greater percentage of attacks treated during the double-blind period that were pain-free at 60 (P = 0.005) and 120 min (P = 0.026) than the sham group (n = 123) did. Similar results were seen for attacks with pain relief at 60 (P = 0.025) and 120 min (P = 0.018). For the first attack and all attacks, the nVNS group had significantly greater decreases (vs sham) in pain score from baseline to 60 min (P = 0.029); the decrease was also significantly greater for nVNS at 120 min for the first attack (P = 0.011). Results during the open-label period were consistent with those of the nVNS group during the double-blind period. The incidence of adverse events (AEs) and adverse device effects was low across all study periods, and no serious AEs occurred.CONCLUSIONS: These results further demonstrate that nVNS is an effective and reliable acute treatment for multiple migraine attacks, which can be used safely while preserving the patient's option to use traditional acute medications as rescue therapy, possibly decreasing the risk of medication overuse. Together with its practicality and optimal tolerability profile, these findings suggest nVNS has value as a front-line option for acute treatment of migraine.TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02686034 .